Here, we report five members affected with severe intellectual disability, developmental delays, seizures, and self-mutilation in a large consanguineous family from Saudi Arabia. Clinical whole-exome sequencing in the proband revealed a pathogenic variant in the CRBN gene, which segregated in the family. CRBN protein is known to play a role in memory and learning by regulating the assembly and expression of large-conductance, calcium-activated potassium channels involved in severe neurological disorders. Our study expands the role of CRBN in severe intellectual disability, with an additional feature of self-mutilation reflecting the heterogeneity in the clinical features exhibited by the patients with CRBN mutations. Studies are ongoing to understand the function of the CRBN variant.

(By Atia Sheereen, http://jmg.bmj.com/content/early/2017/01/30/jmedgenet-2016-104117 )